It is often more readable to use the => operator between key/value pairs. The => operator is mostly just a more visually distinctive synonym for a comma, but it also arranges for its left-hand operand to be interpreted as a string if it's a bareword that would be a legal simple identifier. => doesn't quote compound identifiers, that contain double colons. This makes it nice for initializing hashes:

It is sometimes called the 'fat comma'. It is usually used to initialize a hash: key => 'value'